• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Windshield Washer Switch Signal | 2 | 1 | 1 | -- |
Windshield Washer Fluid Pump Control | 1 | 1 | 2 | -- |
Windshield Washer Relay Control | B3873 02 | B3873 04 | B3873 01 | -- |
Windshield Washer Fluid Pump Ground | -- | 1 | -- | -- |
Windshield Washer Switch Heated Wash Signal | 4 | 3 | 3 | -- |
Heated Washer Nozzle Module B+ | 3 | 3 | -- | -- |
Washer Fluid Heater Enable | B371B 02 | 3 | 3 | -- |
Heated Washer Nozzle Module Ground | -- | 3 | 3 | -- |
Heated Washer Nozzle Module Indicator Signal | 6 | 5 | 5 | -- |
Washer Fluid Level Switch Signal | 8 | 7 | 7 | -- |
Washer Fluid Level Switch Ground | -- | 7 | -- | -- |
1. Front Washer Inoperative 2. Front Washer Always ON 3. Heated Washer Inoperative 4. Heated Washer Always ON 5. Heated Washer Nozzle Module Indicator Inoperative 6. Heated Washer Nozzle Module Indicator Always ON 7. Washer Fluid Level Indicator Inoperative 8. Washer Fluid Level Indicator Always ON |
The body control module (BCM) controls the windshield washer fluid pump based on an input from the turn signal / multifunction switch. The BCM monitors the washer switch through the windshield washer switch signal circuit. When the wash switch is closed, ground is supplied to the windshield washer switch signal circuit. When this is the case, the BCM will command the windshield washer fluid pump and the low speed wipers on.
The intent of the heated washer fluid feature is to automatically clear the windshield of snow or ice upon activation. The system may also be used to improve the bug clearing performance of the wash feature under summer driving conditions.
On some vehicles warning information (wash fluid low and heated wash ON / OFF) will be conveyed via the GMLAN to the controls and displays subsystem (responsible for display). This subsystem will provide visual feedback to the customer while in the RUN power mode.
Wiper/Washer System Description and Operation
Control Module References for scan tool information
⇒ | If the value does not change, refer to Multifunction Switch Malfunction. |
⇒ | If the G24 Windshield Washer Fluid Pump does not run, refer to Washer Pump Malfunction. |
⇒ | If the heated washer function does not work, refer to Heated Washer Malfunction. |
Note: You must perform the Circuit / System Verification before proceeding with Circuit / System Testing.
⇒ | If greater than the specified value, test the low reference circuit for an open / high resistance. If the circuit tests normal, replace the S78 Turn Signal / Multifunction Switch. |
⇒ | If less than the specified value, test the signal circuit terminal 25 for a short to ground. If the circuit tests normal, replace the S78 Turn Signal/Multifunction Switch. |
⇒ | If the test lamp illuminates, test the control circuit for a short to voltage. |
⇒ | If the test lamp does not illuminate, test the ground circuit for an open / high resistance. |
⇒ | If greater than the specified value, test the ground circuit for an short to voltage or an open / high resistance. |
⇒ | If all circuits test normal, replace the X50A Fuse Block - Underhood Primary. |
⇒ | If the test lamp does not illuminate, test the ground circuits for an open / high resistance or a short to voltage and the B+ circuit for an open / high resistance or a short to ground. |
⇒ | If greater than the specified value, test the control circuit for a short to voltage or an open / high resistance. |
⇒ | If the test lamp does not illuminate, test the signal circuit for an open / high resistance or a short to ground. |
⇒ | If greater than the specified value, test the ground circuit for a short to voltage or an open / high resistance. |
⇒ | If greater than the specified value, test the signal circuit for a short to voltage or an open / high resistance. |
⇒ | If the low washer fluid indicator display stays always ON or always OFF, replace the P16 Instrument Cluster. |
⇒ | If the heated washer fluid indicator display stays always ON or always OFF, replace the P16 Instrument Cluster. |
⇒ | If all circuits test normal, test or replace the K80 Heated Washer Nozzle Module. |
⇒ | If not the specified value, test the control circuit for a short to ground. |
⇒ | If greater than the specified value, test the control circuit for a short to voltage or an open / high resistance. |
⇒ | If greater than the specified value, test the control circuit for a short to voltage or an open / high resistance. |
⇒ | If the G24 Windshield Washer Fluid Pump does not activate, replace the G24 Windshield Washer Fluid Pump. |
⇒ | If not the specified range, replace the B118B Windshield Washer Fluid Level Switch. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, setup, and programming |
• | LINK X, for UEC replacement. |
• | LINK X, for Heated Washer Nozzle Module. |